Frame Tagging

Alex Bligh alex at
Thu Aug 1 21:14:21 UTC 2013

On 1 Aug 2013, at 21:22, George Sexton wrote:

>> The first thing I would do to debug this is to use a switch that takes
>> tagged packets in one port, and puts untagged packets on the VLAN you
>> want to configure out another port.   If that fixes it, then you're
>> done, unless you really want to spend a lot more than 27 hours diving
>> into the code!
> The problem is that DHCP is seeing the packets come in on both the VLAN
> tagged interface, and the regular interface, and responding on both. This
> response on both the tagged and untagged interfaces is getting sent back to
> the clients, causing weird things to happen.

I vaguely recall something similar. If you are on Linux you might try
using ebtables to drop processing of the untagged frame.

Alex Bligh

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